Jörn Budde

Effect of liquid hot water pre-treatment on sugarcane press mud methane yield.

Sugarcane press mud was pretreated by liquid hot water (LHW) at different temperatures (140-210 °C) and pre-treatment times (5-20 min) in order to assess the effects on the chemical oxygen demand (COD) solubilisation, inhibitors formation and methane yield. The experimental results showed that a high degree of biomass solubilisation was possible using LHW. Higher methane yields were obtained at lower severities (log(Ro) = 2.17-2.77) with (i) mild temperatures (140-150 °C) and long contact times (12.5 min, 20 min) or (ii) mild temperatures (175 °C) with short contact time (2 min). The highest increase in methane yield (up to 63%) compared to the untreated press mud was found at 150 °C for 20 min. At temperatures of 200 °C and 210 °C, low methane efficiency was attributed to the possible formation of refractory compounds through the Maillard reaction.

Effects of thermobarical pretreatment of cattle waste as feedstock for anaerobic digestion.

Lab-scale experiments were conducted to assess the impact of thermobarical treatment of cattle waste on anaerobic digestion. Treatment was at temperatures of 140-220°C in 20K steps for a 5-min duration. Methane yields could be increased by up to 58% at a treatment temperature of 180°C. At 220°C the abundance of inhibitors and other non-digestible substances led to lower methane yields than those obtained from untreated material. In an extended analysis it could be demonstrated that there is a functional correlation between the methane yields after 30 days and the formation rate and methane yield in the acceleration phase. It could be proved in a regression of these correlation values that the optimum treatment temperature is 164°C and that the minimum treatment temperature should be above 115°C.

Energy balance, greenhouse gas emissions, and profitability of thermobarical pretreatment of cattle waste in anaerobic digestion.

In this study modeled full scale application of thermobarical hydrolysis of less degradable feedstock for biomethanation was assessed in terms of energy balance, greenhouse gas emissions, and economy. Data were provided whether the substitution of maize silage as feedstock for biogas production by pretreated cattle wastes is beneficial in full-scale application or not. A model device for thermobarical treatment has been suggested for and theoretically integrated in a biogas plant. The assessment considered the replacement of maize silage as feedstock with liquid and/or solid cattle waste (feces, litter, and feed residues from animal husbandry of high-performance dairy cattle, dry cows, and heifers). The integration of thermobarical pretreatment is beneficial for raw material with high contents of organic dry matter and ligno-cellulose: Solid cattle waste revealed very short payback times, e.g. 9 months for energy, 3 months for greenhouse gases, and 3 years 3 months for economic amortization, whereas, in contrast, liquid cattle waste did not perform positive replacement effects in this analysis.

Production of xylooligosaccharides from renewable agricultural lignocellulose biomass

Efficient utilization of lignocellulosic biomass requires pretreatment in order to liberate cellulose from lignin and disrupt its recalcitrant crystalline structure before effective enzymatic hydrolysis can take place. Three different pretreatment methods (pressure cooking with dilute alkali and dilute acid as well as alkaline extraction) to recover the xylooligosaccharides fraction from five different grass silage samples, whole crop rye silage and maize silage were compared. The predominant end products released were xylobiose, xylotetraose, xylopentaose and xylohexaose whereas the xylooligosaccharides release pattern differed with the substrate. Maximum values of xylooligosaccharides was found for grass silage 17.26 g/L, whole crop rye silage 3.06 g/L and for maize silage 5.77 g/L. Results reveal the production of high value by-products from agricultural biomass. Advantages of the green-biorefinery concept include a resulting liquid fraction after pretreatment with very low contents of inhibitors such as furfural, hydroxymethylfurfural (HMF) and phenolic compounds.

Software Application in Machine Vision Investigation of Agricultural Seeds Quality

The paper tries to analyze the possibilities of classification of hemp fiber plant seeds in order to provide an image recognition sorting system that can estimate the quality of the fiber hemp seeds destined for human consumption. Systems that can optically grade cereal grains are already available in the agricultural industry. The automatic classification systems for seeds take in consideration the size, shape, color and texture in order to assess the quality of nutritional seeds.This work investigates the classification possibilities of image systems using photo images acquired by an RGB camera. The article presents the experimental stand and devices used for the image analysis of the fiber hemp seeds probes. The method for the selection of the representative pixels of the quality seeds is described and finally the results for the classification of the ratio of ripe seeds versus unripe seeds are presented in graphs. Conclusions are formulated and discussed.