A new version of process synthesizer MIPSYN was developed. Its main advantage is the capability for synthesizing and designing sustainable chemical and biochemical processes. The software is an extension of the previous computer package PROSYN developed together with Prof. Ignacio Grossmann from Carnegie Mellon University, Pittsburgh, USA. MIPSYN can be also used for designing other mechanical structures, e.g. dam gates, composite beams, steel structures etc., which makes MIPSYN a unique interdisciplinary design tool on a worldwide level.
This paper presents a mathematical model for design and optimization of biogas processes from organic and animal wastes. The operating conditions of anaerobic fermentation (thermophilic or mesophilic) are determined simultaneously with the selection of different organic and animal wastes from either existing or new plants, different water supplies, transportation paths and wastewater treatments. The model was applied to an existing large-scale meat company. The economically optimal solution efficiently integrates biogas process with its service facilities within a company.
A synthesis model for biogas process design was upgraded for simultaneous heat integration, and applied to a food company. It was shown that significant benefit can be achieved with heat integration. Almost the complete consumption of hot utility and 1/3 of cold utility can be saved. Most of the electricity and heat produced in the cogeneration system from biogas can be sold to the distribution networks. Optimal heat-integrated biogas process could improve the economic performance and reduce environmental impact by converting environmentally harmful wastes into valuable products.
A model was developed which optimizes the production and distribution of energy and products within regional renewable supply chains. The environmental impact is evaluated by the carbon footprint. The sensitivity analyses are performed for different regions’ sizes, transportation costs, pre-processing alternatives and co-production of food and energy. Since the production of energy is economically more favorable than the cultivation of food, the optimization maximizes the consumption of crops for energy. Additional constraints have to be embedded in the model to fulfil food demands.
The use of brewery’s leftover as a substrate ingredient for Pleurotus ostreatus fruiting body cultivation and enzyme production is presented. Substrates containing various proportions of fresh spent brewery grains, wheat bran, beech sawdust and CaCO3 were used to determine P. ostreatus mycelium growth rate, enzyme activity and the biological efficiency of acquired fruiting bodies to find the optimal substrate composition. It was established that brewery’s leftover is a suitable substrate for fungi cultivation if mixed with other ingredients in proper ratio which influences the growth rate.