Synew Technologies

Powai, India

Synew Technologies

Powai, India

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Shenoy A.U.,Indian Institute of Management | Shenoy U.V.,Synew Technologies
Journal of Cleaner Production | Year: 2015

Zero wastewater discharge (ZWD) networks are targeted and designed in this work by an analytical approach not requiring graphical constructions. The approach is based on three fundamental equations that entail the following requirements for ZWD: (1) the system water loss is entirely made up by freshwater; (2) the net system contaminant load equals the regeneration load; and (3) the net belowpinch contaminant load is picked up by the minimum regenerated water and freshwater. The Unified Targeting Algorithm (UTA) is used to determine the minimum regeneration flowrate and identify the pinch concentration. Necessary conditions are established for pinch jumps and for ZWD feasibility in terms of the maximum post-regeneration outlet concentration. Importantly, continuous targeting is possible over the entire feasible ZWD range through two elegant formulas, wherein (1) the regeneration flowrate is inversely proportional to the concentration reduction during regeneration and (2) the preregeneration concentration decreases linearly with post-regeneration concentration provided the pinch is held by the same point. The Enhanced Nearest Neighbors Algorithm (NNA) is utilized to systematically synthesize ZWD networks over the entire ZWD range and ascertain the network topology valid within sub-ranges. Case studies, including one for a paper mill and another for an alumina plant, are presented to illustrate the versatility of the approach in generating superior practical designs for ZWD networks involving fixed contaminant-load and fixed flowrate processes with and without water loss. © 2014 Elsevier Ltd. All rights reserved.


Shenoy A.U.,Indian Institute of Management | Shenoy U.V.,Synew Technologies
Energy Conversion and Management | Year: 2014

Bioethanol networks with purification for processing pathways in integrated biorefineries are targeted and designed in this work by an analytical approach not requiring graphical constructions. The approach is based on six fundamental equations involving eight variables: two balance equations for the stream flowrate and the bioethanol load over the total network system; one equation for the above-pinch bioethanol load being picked up by the minimum fresh resource and the purified stream; and three equations for the purification unit. A solution strategy is devised by specifying the two variables associated with the purifier inlet stream. Importantly, continuous targeting is then possible over the entire purifier inlet flowrate range on deriving elegant formulae for the remaining six variables. The Unified Targeting Algorithm (UTA) is utilized to establish the minimum fresh bioethanol resource flowrate and identify the pinch purity. The fresh bioethanol resource flowrate target is shown to decrease linearly with purifier inlet flowrate provided the pinch is held by the same point. The Nearest Neighbors Algorithm (NNA) is used to methodically synthesize optimal networks matching bioethanol demands and sources. A case study of a biorefinery producing bioethanol from wheat with arabinoxylan (AX) coproduction is presented. It illustrates the versatility of the approach in generating superior practical designs with up to nearly 94% savings for integrated bioethanol networks, both with and without process constraints, for grassroots as well as retrofit cases. © 2014 Elsevier Ltd. All rights reserved.


Shenoy A.U.,Indian Institute of Management | Shenoy U.V.,Synew Technologies
Energy | Year: 2013

CWNs (cooling water networks) are targeted and designed in this work by an analytical approach requiring no graphical procedures. The key basis for the approach is the conversion of the cooling duties to equivalent inlet-outlet (demand-source) pairs. The UTA (Unified Targeting Algorithm) is first used to establish the minimum CW (cooling water) flowrate and identify the pinch temperature. The Enhanced NNA (Nearest-Neighbors Algorithm) is then utilized to systematically synthesize CWNs by giving priority to LR (local-recycle) matches. The flowrate of the LR match is maximized wherever possible by choosing the neighbor source as the cleanest available source rather than the nearest neighbor. This is advantageous because LR matches can be eliminated for fixed load operations to yield relatively simple network designs that not only meet the minimum CW flow target but also minimize the flowrate through the coolers resulting in reduced network cost. Two case studies are presented to illustrate the versatility of the approach in generating multiple optimum network designs for maximum reuse, temperature constraints and debottlenecking. Importantly, it is demonstrated that superior practical networks can be designed for temperature constrained CWNs with pinch migration as well as without pinch recognition. © 2013 Elsevier Ltd.


Shenoy U.V.,Synew Technologies
Chemical Engineering Research and Design | Year: 2011

A single algorithm is developed to establish minimum resource targets for diverse process integration problems including those of heat/mass exchange, water, hydrogen, carbon emission and material reuse networks. Previous algorithms such as the problem table algorithm for heat exchange networks and the composite table algorithm for resource allocation networks are special cases of the newly proposed unified targeting algorithm (UTA). The conversion of streams to equivalent inlet-outlet (demand-source) pairs is shown to be a key basis for the unified approach. The tabular data from the UTA may be plotted to obtain the grand composite curve (GCC) or the limiting composite curve (LCC). These provide graphical representations of the net load deficit/surplus at various levels for resource targeting and pinch identification. For allocation networks with system loss/gain, the UTA with increasing level sort order yields the Deficit LCC to target the minimum resource, whereas the UTA with decreasing level sort order provides the Surplus LCC to target the minimum waste/excess. A single UTA calculation along with the use of fundamental overall system balance equations is sufficient to establish complete targets for a problem. Six practical case studies from diverse domains are presented to illustrate the detailed steps of the UTA. © 2011 The Institution of Chemical Engineers.


Shenoy U.V.,Synew Technologies
Chemical Engineering Science | Year: 2010

In this work, the unified conceptual approach developed earlier for water and hydrogen networks is extended to energy allocation networks for reduced carbon emissions. The approach involves two distinct stages, namely, targeting and network design. The composite table algorithm (CTA), based on the limiting composite curve, is first used to target the minimum clean energy resources (zero-carbon and/or low-carbon) required in energy sector planning problems with carbon emission constraints aimed at reducing climate change effects. The nearest neighbors algorithm (NNA), where each demand is satisfied by sources that are the nearest available neighbors in terms of emission factor, is then used to synthesize energy allocation networks to meet the already-established targets. Importantly, the NNA allows several network designs, all achieving the minimum resource target, to be systematically generated depending on the order in which the demands are satisfied. Two case studies are presented to illustrate the algorithms. © 2010 Elsevier Ltd.


Shenoy U.V.,Synew Technologies
Chemical Engineering Science | Year: 2012

The Nearest Neighbors Algorithm (NNA) provides a reliable synthesis tool for systematically designing water networks involving fixed flowrate (FF) operations. The Enhanced NNA in this work extends the applicability of the algorithm to fixed contaminant-load (FC) operations by giving priority to local-recycle (LR) matches. The flowrate of the LR match is maximized by choosing the neighbor source as the cleanest available source rather than the nearest neighbor. Subsequently, the LR matches are eliminated for FC operations to yield relatively simple network designs that not only satisfy the minimum freshwater target but also minimize the water flowing through the process units resulting in reduced network cost. The flowrate calculation for neighbor sources in the Enhanced NNA is simplified requiring mere substitution in formulae rather than the earlier simultaneous solution of flow and load balance equations. Case studies are presented to illustrate the versatility of the Enhanced NNA in generating multiple optimum network designs, handling hybrid water network problems where both FF and FC operations coexist, and designing superior practical networks with regeneration including zero wastewater discharge. © 2012 Elsevier Ltd.


Shenoy A.U.,Narsee Monjee Institute of Management and Higher Studies | Shenoy U.V.,Synew Technologies
Chemical Engineering Science | Year: 2012

The mathematical formulation for targeting during energy allocation with carbon capture and storage (CCS) is formally developed. For operating-cost optimization with zero excess, it is shown that CCS sources may be regarded as resources with their cost taken as the increment over the non-CCS option. CCS sources along with clean-carbon resources may then be targeted by profile matching with the limiting composite to establish optimal primary cases. The limiting composite curve is itself sacrosanct and obtained by a single computation of the composite table algorithm (CTA) including only non-CCS sources. Carbon emission networks (CENs) are designed by the nearest neighbors algorithm (NNA). A cost criterion is established to determine cost-factor ranges for optimality of the primary cases, and results validated by solving linear programming (LP) and mixed integer linear programming (MILP) formulations. The methodology essentially comprises four distinct stages - targeting, network design, cost analysis, and optimization - with the first two stages not requiring any cost data. © 2011 Elsevier Ltd.

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