As a promising approach for carbon dioxide capture, chemical looping combustion has been extensively investigated for more than two decades. However, the chemical looping strategy can be and has been extended well beyond carbon capture. In fact, significant impacts on emission reduction, energy conservation, and value-creation can be anticipated from chemical looping beyond combustion (CLBC). This article aims to demonstrate the versatility and transformational benefits of CLBC. Specifically, we focus on the use of oxygen carriers or redox catalysts for chemical production – a $4 trillion industry that consumes 40.9 quadrillion BTU of energy. Compared to state-of-the-art chemical production technologies, we illustrate that chemical looping offers significant opportunities for process intensification and exergy loss minimization. In many cases, an order of magnitude reduction in energy consumption and CO2 emission can be realized without the needs for carbon dioxide capture. In addition to providing various CLBC examples, this article elaborates on generalized design principles for CLBC, potential benefits and pitfalls, as well as redox catalyst selection, design, optimization, and redox reaction mechanism.

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Chemical looping beyond combustion – a perspective

Most C4 hydrocarbons are obtained as byproducts of ethylene production or oil refining, and complex and energy-intensive separation schemes are required for their isolation. Substantial industrial and academic effort has been expended to develop more cost-effective adsorbent- or membrane-based approaches to purify commodity chemicals such as 1,3-butadiene, isobutene, and 1-butene, but the very similar physical properties of these C4 hydrocarbons make this a challenging task. Here, we examine the adsorption behavior of 1-butene, cis-2-butene, and trans-2-butene in the metal-organic frameworks M2(dobdc) (M = Mn, Fe, Co, Ni; dobdc4- = 2,5-dioxidobenzene-1,4-dicarboxylate) and M2(m-dobdc) (m-dobdc4- = 4,6-dioxidobenzene-1,3-dicarboxylate), which all contain a high density of coordinatively unsaturated M2+ sites. We find that both Co2(m-dobdc) and Ni2(m-dobdc) are able to separate 1-butene from the 2-butene isomers, a critical industrial process that relies largely on energetically demanding cryogenic distillation. The origin of 1-butene selectivity is traced to the high charge density retained by the M2+ metal centers exposed within the M2(m-dobdc) structures, which results in a reversal of the cis-2-butene selectivity typically observed at framework open metal sites. Selectivity for 1-butene adsorption under multicomponent conditions is demonstrated for Ni2(m-dobdc) in both the gaseous and the liquid phases via breakthrough and batch adsorption experiments.

Thermodynamic Separation of 1-Butene from 2-Butene in Metal-Organic Frameworks with Open Metal Sites.

Selective dimerization of 1-butene on Ni exchanged zeolite LTA to n-octene and methyl heptene occurs via Cossee-Arlman mechanism. With increasing conversion, isomerization to 2-butene led also to dimethylhexene and catalyst deactivation. Dimerization of 1-butene was an order of magnitude faster than dimerization of 2-butene. The presence of alkali and alkali earth cations increased the isomerization rates, but did not affect the dimerization activity of Ni sites, allowing to reach higher selectivities to n-octene and methylheptenes.

Dimerization of 1-Butene on Ni Based Solid Catalysts

The book treats the C -hydrocarbons and their secondary products as a contribution 4 to chemical engineering economics, applying this field of teaching and research to the technical processes for making and processing this group of products, so important to the chemical industry As early as tpe 1950s the then director of the Institute for Technical Chemistry of the Berlin Technical University, Professor Herbert Kolbel, took the' initiative in the domain of Chemical Engineering Economics and began systematic studies of Project Engineering and Cost Estimation in connection with chemical plants He also started a course on technical chemical processes in 1966 Properties, production procedures, plant equipment, and also the uses of technically interesting products are the central features of Chemical Technology The information is to be found in the large encyclopedias of Technical Chemistry On the other hand, Chemical Engineering Economics deals with all the economic conditions of usage of the raw materials, possibilities of utilizing co-products, and the integration of these products into definite production programmes, from the stand point of the chemical and technical fundamentals of the processes Further important viewpoints are the costs of the products, taking into consideration important and variable influences on these costs, the situation and development of the market for the products and, of increasing significance, also the ecological global conditions for procuring raw materials and the production and marketing of the particular products"

Joachim Schulze

Papers

C 4 -Hydrocarbons and Derivatives: Resources, Production, Marketing