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arXiv · 2608.06131

ChromOps.jl: High-order simulation and discrete forward sensitivity analysis for chromatography models

Kristian Meyer·Maksym Ratajczyk·Christopher Rackauckas
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Abstract

Mechanistic chromatography models are valuable for process development, but gradient-based parameter estimation and optimization can be hindered by computational cost and the effort of deriving objective-function gradients. To address this concern, a fully differentiable Julia chromatography solver, ChromOps.jl, is presented that combines high-order spatial discretization with discrete forward sensitivity analysis (DFSA). Two high-order spatial discretizations, finite difference summation-by-parts (FD-SBP) and the discontinuous Galerkin spectral element method (DG-SEM), are compared on a 6-component ion-exchange chromatography problem with steric mass action kinetics. Both attain their theoretical convergence rates on manufactured problems, while FD-SBP shows favourable work-precision performance for both forward (primal) and dual-valued simulations and is conceptually simpler to implement. DFSA scales as tDFSA approx 1.4(1+Np)tfwd for up to Np = 24 parameters propagated in a single ForwardDiff.jl chunk, i.e. about 1.4 forward solves per additional parameter. Because the primal and dual-valued solves share the same code path, DFSA provides accurate gradients of user-defined objectives without any hand-derived chain-rule code, enabling accessible gradient-based parameter estimation and optimization.

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Kristian Meyer, Maksym Ratajczyk, Christopher Rackauckas. 2026-08-06. ChromOps.jl: High-order simulation and discrete forward sensitivity analysis for chromatography models. https://arxiv.org/abs/2608.06131

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