Joakim Lundgren

Combustion of horse manure for heat production

The main objectives of this paper have been to evaluate the use of horse manure and wood-shavings as a fuel for heat production and to provide sets of data on the chemical composition, ash characteristics and ash forming elements of the fuel. Another objective has been to investigate the possibility to use the ash as fertiliser by analysing the heavy metal and nutrient contents. The results showed that the fuel is well suited for combustion for heat production causing low emissions of products of incomplete combustion. The emissions of NO(x) were however high due to the high content of fuel bound nitrogen. Emissions of CO and NO(x) were typically in the range of 30-150 mg/Nm(3) and 280-350 mg/Nm(3) at 10 vol% O(2), respectively. The analysis of the ash showed on sufficiently low concentration of heavy metals to allow recycling.

Black liquor fractionation for biofuels production - a techno-economic assessment.

The hemicelluloses fraction of black liquor is an underutilized resource in many chemical pulp mills. It is possible to extract and separate the lignin and hemicelluloses from the black liquor and use the hemicelluloses for biochemical conversion into biofuels and chemicals. Precipitation of the lignin from the black liquor would consequently decrease the thermal load on the recovery boiler, which is often referred to as a bottleneck for increased pulp production. The objective of this work is to techno-economically evaluate the production of sodium-free lignin as a solid fuel and butanol to be used as fossil gasoline replacement by fractionating black liquor. The hydrolysis and fermentation processes are modeled in Aspen Plus to analyze energy and material balances as well as to evaluate the plant economics. A mathematical model of an existing pulp and paper mill is used to analyze the effects on the energy performance of the mill subprocesses.

Techno-economic assessment of catalytic gasification of biomass powders for methanol production

This study evaluated the techno-economic performance and potential benefits of methanol production through catalytic gasification of forest residues and lignin. The results showed that while catalytic gasification enables increased cold gas efficiencies and methanol yields compared to non-catalytic gasification, the additional pre-treatment energy and loss of electricity production result in small or no system efficiency improvements. The resulting required methanol selling prices (90-130€/MWh) are comparable with production costs for other biofuels. It is concluded that catalytic gasification of forest residues can be an attractive option as it provides operational advantages at production costs comparable to non-catalytic gasification. The addition of lignin would require lignin costs below 25€/MWh to be economically beneficial.

Techno-economics of carbon preserving butanol production using a combined fermentative and catalytic approach

This paper presents a novel process for n-butanol production which combines a fermentation consuming carbon dioxide (succinic acid fermentation) with subsequent catalytic reduction steps to add hydrogen to form butanol. Process simulations in Aspen Plus have been the basis for the techno-economic analyses performed. The overall economy for the novel process cannot be justified, as production of succinic acid by fermentation is too costly. Though, succinic acid price is expected to drop drastically in a near future. By fully integrating the succinic acid fermentation with the catalytic conversion the need for costly recovery operations could be reduced. The hybrid process would need 22% less raw material than the butanol fermentation at a succinic acid fermentation yield of 0.7g/g substrate. Additionally, a carbon dioxide fixation of up to 13ktonnes could be achieved at a plant with an annual butanol production of 10ktonnes.

Experimental studies during heat load fluctuations in a 500 kW wood-chips fired boiler

Abstract Several long-term experiments with fluctuating thermal outputs have been carried out in a newly developed biomass fuelled boiler suitable for small district heating networks. The experiments have been performed by either using the furnace only or the furnace together with a water heat store. Comparisons between these two operation strategies have been made concerning emissions and overall performance. Furthermore, the plant has been run to match a simulated heat demand during different seasons, in order to study the performance of the system during more realistic operation conditions. The results are very satisfactory concerning both performance and emissions, using any of the control strategies. Typical emissions of CO and NOx during the experiments are in the range of 10– 50 mg Nm −3 (5– 25 mg MJ −1 ) and 130– 175 mg Nm −3 (60– 90 mg MJ −1 ), respectively. However, during summer when the heat demand is low or zero, operational problems will occur if the heat store is excluded. Therefore, the main conclusion is that the most appropriate solution for a small district-heating system is to use a water heat store to match the heat load variations, while the furnace operates at as constant thermal output as possible.

Process simulation and energy optimization for the pulp and paper mill

A process integration model is developed based on mixed integer linear programming. The analysis is carried out using the reMIND software in combination with the commercial optimization software CP ...

Integration of an Electrolysis Unit for Producer Gas Conditioning in a Bio-Synthetic Natural Gas Plant

Producer gas from biomass gasification contains impurities like tars, particles, alkali salts, and sulfur/nitrogen compounds. As a result, a number of process steps are required to condition the pr ...

Biomass gasification fundamentals to support the development of BTL in forest industry

The Nordic forest industry creates new concepts and provides solutions to mitigate climate challenge. One of the most interesting concepts is the integrated production of pulp and paper products and transportation fuels. The Finnish and Swedish activities are aiming to the same objective increased profitability of pulp and paper industry by using their by-products for producing high-quality renewable fuels. The technical approaches are different. For the technologies the scientific co-operation in the R & D consortium of VTT-ETC-LTU-SINTEF created background know-how through experiments and modelling in NORDSYNGAS project realised between 2010–2014. The objective of the project was to create new scientific knowledge on fluidised-bed and entrained-flow gasification of biomass residues and black liquor in order to support the Nordic industrial development and demonstration projects. In addition, close co-operation between the Finnish, Swedish and Norwegian R&D organisations was organised. ISBN, ISSN ISBN 978-951-38-8220-4 (URL: http://www.vtt.fi/publications/index.jsp) ISSN-L 2242-1211 ISSN 2242-122X (Online)