Scrubber

A micro-gas analysis system, μGAS, is proposed here for the continuous and highly sensitive on-site measurement of atmospheric trace gases. The μGAS presented here is comprised of a microchannel scrubber and a high-sensitivity small fluorescence detector. The key to the μGAS is the fabrication of a good gas permeable membrane on a shallow channel to allow for the efficient accumulation of the analyte into the absorbing solution. The channel is formed by micromachining, and a gas permeable membrane of any desired thickness is formed by spin-coating on a fluorosilane-treated substrate. In this work, polydimethylsiloxane was used for both the channel block and the gas permeable membrane, and were easily tightly bonded. The microchannel structure ensures a high sensitivity, and the sensitivity is inversely proportional to the membrane thickness. The device, including the air supply function, is set in only 30-mm-cube. The performance of the μGAS has been demonstrated as a H2S gas sensor. The μGAS consumes only 1ml of the reagent solution in 8h of operation with a detection limit of 1ppbv.

This paper will explore Amager Bakke, focusing first on the process by which the plant generates energy from waste combustion. This will provide the  context to then delve into the contaminant removal process, a discussion that will cover the relevance of the possible emissions, and by extension, the implications for the air quality in the surrounding communities. Subsequently, a more detailed walk-through of the hypothetical design of such a system will provide a more complete understanding of contaminant removal from the effluent waste stream (flue gas). This will include an analysis of the cost and implications of such a system. Finally, the paper will conclude with a review of the ethical principles surrounding waste-to-energy plants, including responsible parties, ethical dilemmas, and measures to prevent malpractice.

Biogas production is one of the most promising pathways toward fully utilizing green energy within a circular economy. The anaerobic digestion process is the industry standard technology for biogas production due to its lowered energy consumption and its reliance on microbiology. Even in such an environmental-friendly process, liquid digestate is still produced from the remains of digested bio-feedstock and will require treatment. With unsuitable treatment procedure for liquid digestate, the mass of bio-feedstock can potentially escape the circular supply chain within the economy. This paper recommends the implementation of evaporator systems to provide a sustainable liquid digestate treating mechanism within the economy. Studied evaporator systems are represented by vacuum evaporation in combination with ammonia scrubber, stripping and reverse osmosis. Nevertheless, complex multi-dimensional decisions should be made by stakeholders before implementing such systems. Our work utilizes a novel techno-economics model to study the techno-economics robustness in implementing recent state-of-art vacuum evaporation systems with exploitation of waste heat from combined heat and power (CHP) units in biogas plants (BGP). To take into the account the stochasticity of the real world and robustness of the analysis, we used the Monte-Carlo simulation technique to generate more than 20,000 of different possibilities for the implementation of the evaporation system. Favourable decision pathways are then selected using a novel methodology which utilizes the artificial neural network and a hyper-optimized decision tree classifier. Two pathways that give the highest probability of providing a fast payback period are identified. Descriptive statistics are also used to analyse the distributions of decision parameters that lead to success in implementing the evaporator system. The results highlighted that integration of evaporation system are favourable when transport costs and incentives for CHP units are large and while feed-in tariffs for electricity production and specific investment costs are low. The result of this work is expected to pave the way for BGP stakeholders and decision makers in implementing liquid digestate treating technologies within the currently existing infrastructure.

It is a well-known fact that the Marine Environment Protection Committee (MEPC) confirmed that the sulfur content in marine fuel should be at least 0.5% by January 1, 2020. Thus, shipowners have two options: to install air treatment devices on their ships or use fuel with low sulfur content.
So what is better - the installation of scrubber systems or the use of LS fuel (with 0.5% sulfur content)?