Bruno Fabiano

Thermodynamic study and optimization of hydrogen production by Enterobacter aerogenes

Abstract This paper investigates the influence of pH and temperature on hydrogen bioproduction by Enterobacter aerogenes (NCIMB 10102) utilizing starch hydrolysate as substrate. An optimum pH range corresponding to 6.1–6.6 is the main evidence of batch runs carried out at different pHs. An optimum value of temperature corresponding to 40°C is experimentally determined by means of batch fermentation runs carried out at different operative temperatures. A thermodynamic study, which was performed developing the Arrhenius approach, allows the estimation, for both fermentation and thermal inactivation, of the activation enthalpies (67.3 and 118.1 kJ mol −1 ) and of the correlated entropies (−0.087 and −0.46 kJ mol −1 K −1 ).

A framework for risk assessment and decision-making strategies in dangerous good transportation

The risk from dangerous goods transport by road and strategies for selecting road load/routes are faced in this paper, by developing an original site-oriented framework of general applicability at local level. A realistic evaluation of the frequency must take into account on one side inherent factors (e.g. tunnels, rail bridges, bend radii, slope, characteristics of neighborhood, etc.) on the other side factors correlated to the traffic conditions (e.g. dangerous goods trucks, etc.). Field data were collected on the selected highway, by systematic investigation, providing input data for a database reporting tendencies and intrinsic parameter/site-oriented statistics. The developed technique was applied to a pilot area, considering both the individual risk and societal risk and making reference to flammable and explosive scenarios. In this way, a risk assessment, sensitive to route features and population exposed, is proposed, so that the overall uncertainties in risk analysis can be lowered.

Process development of continuous hydrogen production by Enterobacter aerogenes in a packed column reactor

Abstract Hydrogen bioproduction from agro-industrial residues by Enterobacter aerogenes in a continuous packed column has been investigated and a complete reactor characterization is presented. Experimental runs carried out at different residence time, liable of interest for industrial application, showed hydrogen yields ranging from 1.36 to 3.02 mmolH2mmol−1glucose or, in other words, from 37.5% to 75% of the theoretical hydrogen yield. A simple kinetic model of cell growth, validated by experimental results and allowing the prediction of biomass concentration profile along the reactor and the optimization of superficial velocity, is suggested. By applying the developed approach to the selected operative conditions, the identification of the optimum superficial velocity v0,opt of about 2.2 cm h−1 corresponding to the maximum hydrogen evolution rate H˙2g,max, was performed.

A review of the past, present and future of the European loss prevention and safety promotion in the process industries

Part 1 Volume I: theme 1 - safety, management systems, human reliability - process safety of polymer resin manufacturing - a 20-year perspective, A.S. Balchan et al control system and emergency plan in petrochemical plant, Y. Uehara using a task inventory to develop a more effective incident reporting system, A.J. Brazier and J.M. Black about handling and storage of liquefied gases and volatile liquids safety aspects, F. Degreef and A. Maes theme 2 - hazards research - improved safety of chemical processes by on-line supervision using advanced software tools, L. Hub safety of chlorination reactions, J.L. Gustin and A. Fines validation of mathematical models using wind-tunnel data sets for dense gas dispersion in the presence of obstacles, J. Havens et al the effect of obstacles on dense gas clouds, N.J. Duijm et al theme 3 - methods for safe design, prevention and protection - the safe handling of exothermic reactions and the safe discharge from pressure-relief devices, S. Dress theoretical and experimental investigation of the processes during reactor top venting of a thermal runaway reaction, G. Wehmeier et al the influence of non-equilibrium vapour generation on transient level swell during pressure relief of liquefied gases, B. Boesmans and J. Berghmans design of centrifugal separators for emergency vent line systems, J. Schmidt et al theme 4 - risk assessment, including consequence models - hazard identification and evaluation at plant level, J. Suokas computer-aided HAZOP with knowledge-based identification of hazardous event claims, P. Heino et al process safety artificial intelligence system, J.W. Sanders the representation and propagation of parametric uncertainties in consequence models for quantified risk assessment, J. Quelch and I.T. Cameron. Part 2 volume II. theme 1 - safety, management systems, human reliability - the AVRIM safety inspection method, J.I.H. Oh internal control system at three Finnish explosives factories, J. Karhulahti toxic and inflammable/explosive chemicals - a Swedish manual for risk assessment, R. Forsen the role of predictive maintenance in work accident prevention, I. Cheema theme 2 - hazards research - runaway reaction hazard assessment based on the recognition of dangerous process situations or process deviations choice of prevention and mitigation measures, J.L. Gustin further development of the unified dispersion model, J. Cook and J.L. Woodward application of the one-dimensional model UPMFIRE to calculate jet fire characteristics and its interaction with obstacles, A. Crespo et al experimental research of heavy gas dispersion mechanism and creation of advanced tool for vapor cloud dispersion modelling, O.V. Dobrocheev et al theme 3 - methods for safe design, prevention and protection - safety valve reliability, A.B. Smith DACALS - a simple verified VCE model, F.K. Crawley et al. (Part contents).

Macro-kinetic investigation on phenol uptake from air by biofiltration: Influence of superficial gas flow rate and inlet pollutant concentration.

The macro‐kinetic behavior of phenol removal from a synthetic exhaust gas was investigated theoretically as well as experimentally by means of two identical continuously operating laboratory‐scale biological filter bed columns. A mixture of peat and glass beads was used as filter material. After sterilization it was inoculated with a pure strain of Pseudomonas putida, as employed in previous experimental studies. To determine the influence of the superficial gas flow rate on biofilter performance and to evaluate the phenol concentration profiles along the column, two series of continuous tests were carried out varying either the inlet phenol concentration, up to 1650 mg · m−3, or the superficial gas flow rate, from 30 to 460 m3 · m−2 · h−1. The elimination capacity of the biofilter is proved by a maximum volumetric phenol removal rate of 0.73 kg · m−3 · h−1. The experimental results are consistent with a biofilm model incorporating first‐order substrate elimination kinetics. The model may be considered a useful tool in scaling‐up a biofiltration system. Furthermore, the deodorization capacity of the biofilter was investigated, at inlet phenol concentrations up to 280 mg · m−3 and superficial gas flow rates ranging from 30 to 92 m3 · m−2 · h−1. The deodorization of the gas was achieved at a maximum inlet phenol concentration of about 255 mg · m−3, operating at a superficial gas flow rate of 30 m3 · m−2 · h−1.

Occupational injuries in Italy: risk factors and long term trend (1951-98).

OBJECTIVES Trends in the rates of total injuries and fatal accidents in the different sectors of Italian industries were explored during the period 1951–98. Causes and dynamics of injury were also studied for setting priorities for improving safety standards. METHODS Data on occupational injuries from the National Organisation for Labour Injury Insurance were combined with data from the State Statistics Institute to highlight the interaction between the injury frequency index trend and the production cycle—that is, the evolution of industrial production throughout the years. Multiple regression with log transformed rates was adopted to model the trends of occupational fatalities for each industrial group. RESULTS The ratios between the linked indices of injury frequency and industrial production showed a good correlation over the whole period. A general decline in injuries was found across all sectors, with values ranging from 79.86% in the energy group to 23.32% in the textile group. In analysing fatalities, the trend seemed to be more clearly decreasing than the trend of total injuries, including temporary and permanent disabilities; the fatalities showed an exponential decrease according to multiple regression, with an annual decline equal to 4.42%. CONCLUSIONS The overall probability of industrial fatal accidents in Italy tended to decrease exponentially by year. The most effective actions in preventing injuries were directed towards fatal accidents. By analysing the rates of fatal accident in the different sectors, appropriate targets and priorities for increased strategies to prevent injuries can be suggested. The analysis of the dynamics and the material causes of injuries showed that still more consideration should be given to human and organisational factors.

Mathematical modelling and optimization of hydrogen continuous production in a fixed bed bioreactor

The purpose of this paper is to investigate, both theoretically and experimentally, hydrogen production from agro-industrial by-products using a continuous bioreactor packed with a mixture of spongy and glass beads and inoculated with Enterobacter aerogenes. Replicated series of experimental runs were performed to study the effects of residence time on hydrogen evolution rate and to characterize the critical conditions for the wash out, as a function of the inlet glucose concentration and of the fluid superficial velocity. A further series of experimental runs was focused on the effects of both residence time and inlet glucose concentration over hydrogen productivity. A kinetic model of the process was developed and showed good agreement with experimental data, thus representing a potential tool to design a large-scale fermenter. In fact, the model was applied to the optimal design of a bioreactor suitable of feeding a phosphoric acid fuel cell of a target power.

A century of accidents in the Italian industry: Relationship with the production cycle

Abstract The purpose of this paper is to examine the fluctuations of accident frequency in the Italian industry during a period of time covering almost a hundred years (from 1890 to 1989) and to examine possible connections with industrial production fluctuations. Notwithstanding the considerable variations of economic and social conditions and the increasing technological and scientific improvement, the number of accidents never drops below 110 cases per 1000 workers/year. We focused our attention on economic factors, which, especially over the long run, seem to be the most important, so as to set the basic trends in occupational accidents. A nice parallelism between the economic cycle and the trend of accidents has been pointed out, differences not exceeding 20% over the whole period of observations. This relationship affords the oppurtinity to verify that the factors influencing human safety conditions in industrial activities do not depend on technological development.

Systematical analysis of chemical methods in metal nanoparticles synthesis

We propose a short review paper on the mainly adopted techniques for the production of metal nanoparticles in industrial and laboratory scale. The methods are grouped according to the wellknown classification in bottom-up and top-down schemes, with a particular emphasis on the operating conditions specifically adopted. Namely, some aspects concerning the experimental setup, the choice of precursors and reactants and the relevant technical advantages/limitations of the methods are discussed and compared in light of the most recent issues in matter of metal nanoparticles synthesis.

Biodiesel production via transesterification: Process safety insights from kinetic modeling

Biodiesel is an alternative non-petroleum based fuel, consisting of alkyl esters obtained either by esterification of free fatty acids with low molecular weight alcohols, or by transesterification of triglycerides. The realization of a biodiesel unit can pose several safety issues and inherent safety application opportunities as the production involves the transport, use and storage of hazardous materials, either flammable or toxic. In the experimental phase, we studied, at laboratory scale, different alkali catalysts and the relevant reaction parameters, considering inherent safety opportunities. An accurate kinetic model of the transesterification process was developed and validated, allowing to provide possible minimization and simplification plant options.